Lake Ladoga is a freshwater lake located in the Republic of Karelia and Leningrad Oblast in northwestern Russia, in the vicinity of Saint Petersburg. It is the largest lake located entirely in Europe, the second largest lake in Russia after Baikal, and the 14th largest freshwater lake by area in the world. It is comparable in size to Lake Ontario. Ladoga La…Lake Ladoga is a freshwater lake located in the Republic of Karelia and Leningrad Oblast in northwestern Russia, in the vicinity of Saint Petersburg. It is the largest lake located entirely in Europe, the second largest lake in Russia after Baikal, and the 14th largest freshwater lake by area in the world. It is comparable in size to Lake Ontario. Ladoga Lacus, a methane lake on Saturn's moon Titan, is named after the lake.